OBJECTIVES : Despite the prevalence of Parkinson’s disease psychosis (PDP), estimated at up to 50% of patients with Parkinson’s disease (PD), little is known regarding the treatment paradigm. The goal of the INSYTE Study – Management of Parkinson’s Disease Psychosis in Actual Practice – is to gain a better understanding of the management of PDP and treatment outcomes.

METHODS : INSYTE is an ongoing study expected to enroll up to 750 patients and their caregivers from approximately 100 sites; patients are followed for 36 months. INSYTE employs validated assessment instruments, although as an observational study does not impose a pre-defined visit schedule, medical tests, laboratory tests, procedures, or interventions.

RESULTS : Baseline data for 74 patients enrolled to date found that a majority are male (64%), white (96%), and live in a private residence (92%). Average age is 76.4 years (median=75 years). At baseline, 23% had mild/mild to moderate PD, 54% had moderate/moderate to advanced PD, and 23% had advanced PD. Using the Clinical Global Impression Severity Scale, 36% of patients were borderline to mildly mentally ill and 49% were moderately to markedly mentally ill. Most patients, 64%, were diagnosed with PDP about a year prior to study enrollment. Antipsychotic use was reported in 29 (39%) patients, of which 19 used pimavanserin either as monotherapy (n=14; 48%) or in combination with other atypical antipsychotics (n=5; 17%). The second most common antipsychotic used was quetiapine, followed by olanzapine, clozapine and aripiprazole.

CONCLUSIONS : INSYTE is the first large observational study to evaluate how patients with PDP are treated in the real-world setting, and how these treatments affect patients. Initial results indicate that only 39% of PDP patients reported antipsychotic use at baseline despite their diagnosis. Results from this study will inform the scientific community on best practices and potentially inform PDP treatment guidelines and standards of care